Use EmbeddedTestServer provided URL instead of no-port localhost URL.

The ProcessManagerBrowserTest.HostedAppAlerts test uses a hardcoded URL
to localhost without a port number. Since the server runs on non-default
and randomized port number, navigation to URL without port is expected
to fail. This test needs to be updated to ensure navigation succeeds.

Bug: 838161
Change-Id: Iedf309114dfc60f7b10745d96daf6b669f657c14
Reviewed-on: https://chromium-review.googlesource.com/1035363Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Commit-Queue: Nasko Oskov <nasko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#554804}

chrome/browser/extensions/process_manager_browsertest.cc

@@ -1589,8 +1589,13 @@ IN_PROC_BROWSER_TEST_F(ProcessManagerBrowserTest, HostedAppAlerts) {
 
   content::WebContents* tab =
       browser()->tab_strip_model()->GetActiveWebContents();
-  GURL hosted_app_url("http://localhost/extensions/hosted_app/main.html");
-  NavigateToURL(hosted_app_url);
+  GURL hosted_app_url(embedded_test_server()->GetURL(
+      "localhost", "/extensions/hosted_app/main.html"));
+  {
+    content::TestNavigationObserver observer(tab);
+    NavigateToURL(hosted_app_url);
+    EXPECT_TRUE(observer.last_navigation_succeeded());
+  }
   EXPECT_EQ(hosted_app_url, tab->GetLastCommittedURL());
   ProcessManager* pm = ProcessManager::Get(profile());
   EXPECT_EQ(extension, pm->GetExtensionForWebContents(tab));